Mirror with increased reflectance

Abstract

A process for manufacturing mirrors with increased reflectance includes forming a silver layer on a surface of a glass substrate, during which the surface is contacted with a silvering solution, and painting at least one paint layer to cover the silver layer. Between forming the silver layer and the painting, the process includes reheating the silver layer to a temperature of at least 200° C.

The invention claimed is: 
     
       1. A mirror, comprising:
 a glass substrate; 
 a modified silver layer, which is in contact with and covers said glass substrate; and 
 a paint layer, which is in contact with and covers said modified silver layer, wherein 
 a silver-enriched stratum is present within said glass substrate in an area that is in contact with and covered by said modified silver layer, and 
 said silver-enriched stratum has a thickness of at least 10 nm. 
 
     
     
       2. A process of forming a mirror according to  claim 1 , comprising:
 contacting the substrate with a silvering solution to form a silver layer on said substrate; 
 drying the silver layer obtained from said contacting; 
 heating the silver layer to a temperature of at least 200° C., thereby forming a modified silver layer on said substrate and a silver-enriched stratum at an upper side of said substrate that is in contact with and covered by said modified silver layer; 
 painting said modified silver layer with a paint; and 
 drying said paint to form a painted layer in contact with and covering said modified silver layer, 
 wherein said heating the silver layer is carried out after said drying the silver layer and before said painting said modified silver layer. 
 
     
     
       3. The process according to  claim 2 , wherein
 said heating the silver layer is carried out by at least one method selected from the group comprising heating by infrared radiation, convection heating, metal induction and microwave heating. 
 
     
     
       4. The process according to  claim 3 , wherein
 said heating the silver layer is carried out in an atmosphere comprising an inert gas. 
 
     
     
       5. The process according to  claim 3 , wherein said heating is carried out in an atmosphere consisting essentially of an inert gas. 
     
     
       6. The process according to  claim 2 , wherein the mirror has no copper layer. 
     
     
       7. The process according to  claim 2 , further comprising:
 contacting said substrate with a solution comprising at least one element selected from the group consisting of bismuth, chromium, gold, indium, nickel, palladium, platinum, rhodium, ruthenium, titanium, vanadium and zinc, thereby activating said substrate, 
 wherein the activating of said substrate is carried out prior to said contacting the substrate with a silvering solution. 
 
     
     
       8. The process according to  claim 2 , further comprising:
 contacting said modified silver layer with a solution comprising at least one element selected from the group consisting of tin, palladium, vanadium, titanium, iron, indium, copper, aluminium, chromium, lanthanum, nickel, europium, zinc, platinum, ruthenium, rhodium, sodium, zirconium, yttrium and cerium, thereby passivating the modified silver layer. 
 
     
     
       9. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 225° C. during said heating. 
     
     
       10. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 250° C. during said heating. 
     
     
       11. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 275° C. during said heating. 
     
     
       12. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 300° C. during said heating. 
     
     
       13. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 325° C. during said heating. 
     
     
       14. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 350° C. during said heating. 
     
     
       15. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 375° C. during said heating. 
     
     
       16. The process according to  claim 2 , wherein the substrate is heated to a temperature of at least to a temperature of at least 400° C. during said heating. 
     
     
       17. The process according to  claim 2 , wherein heating the silver layer to a temperature of at least 200° C. is carried out for a period of from 1 to 20 minutes. 
     
     
       18. The process according to  claim 2 , wherein the substrate is heated to a temperature of from 200° C. to 700° C. 
     
     
       19. The mirror according to  claim 1 , wherein the silver-enriched stratum has a thickness of at least 20 nm. 
     
     
       20. The mirror according to  claim 1 , wherein the silver-enriched stratum has a thickness of at least 50 nm. 
     
     
       21. The mirror according to  claim 1 , wherein the substrate further comprises an upper surface stratum on the side of the silver layer comprising palladium, and in that this palladium-enriched stratum has a thickness of at least 5 nm. 
     
     
       22. The mirror according to  claim 21 , wherein the palladium-enriched stratum has a thickness of at least 7 nm. 
     
     
       23. The mirror according to  claim 1 , wherein the substrate is an extra-clear glass. 
     
     
       24. The mirror according to  claim 1 , wherein the modified silver layer has a thickness in the range of between 70 and 150 nm. 
     
     
       25. The mirror according to  claim 1 , wherein said mirror comprises tin on the surface of the substrate on the side of the silver layer. 
     
     
       26. The mirror according to  claim 1 , wherein said mirror has no copper layer. 
     
     
       27. The mirror according to  claim 1 , wherein the silver-enriched stratum has a thickness of from 10 nm to 1000 nm.